Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Smog-control affect on performance

First question:
Could someone explain all the ways (or at least as
many ways that you can think of) that pollution
control devices have hurt performance. I know that
engines are smaller, and the catalytic converter
corks up the exhaust flow, but that's about all I
really understand. Can someone elaborate for me?

Second question:
I've heard that you can't compare the
horsepower/torque ratings for the old muscle cars
with those of today. Something about they use
different standards. Can someone explain that?



  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaPosts: 64,482
    First of all, shock of shocks, emissions controls do not hurt performance, especially with the advent of sophisticated computer control systems.

    WAY BACK WHEN, when the state of California was demanding emissions controls and Detroit thumbed their noses (and then the Feds stepped in and made Detroit suffer for their arrogance), back then (early 70s through mid 1980s), emission controls indirectly hurt performance because there were no powerplants that were both powerful and clean.

    But now we have engines that can put out over 100 HP per liter while you can practically inhale from the tailpipe.

    To give you an idea of how clean engines are today, I have a videotape that shows a new Saab's air filter hooked directly into the tailpipe of an old Saab two-stroke (gas-oil mix) the new Saab actually is cleaning the exhaust of the old Saab...AND...when the new Saab's tailpipe emissions were tested, the air coming out was CLEANER than the ambient air of downtown London, where the test was performed (a pretty dirty city, it's true). Amazing, huh?

    Which leads to the second question.

    WAY BACK WHEN, in the days when cars were called 'muscle cars" and men ate red meat unabashedly (1960s), Detroit often LIED (well knock me over with a feather!) about the horsepower ratings of their cars, since the US government was putting pressure on US companies to downplay their involvement in racing. Keep in mind that this was the time when over 50,000 Americans were dying each year on public roads. ANYWAY, since they fibbed on horsepower ratings, the real HP of some of the bigger=engined cars of the 60s is probably underrated.

    But the way one measures HP is the same today as back then...well, basically the same. It may seem like today's single horsepower is a bigger horse than the old ones, but that's because those older cars carried a lot more weight and because today's engines are so much better and more put it in perspective, take something like the monster Buick GS455...that's 455 cubic inches, and 510 ft lbs of torque at 2800 rpms? And the 0-60 time is "only" 6 old Nissan 300ZX Turbo V-6 could beat it.
  • I was confused on the first issue as I kept hearing people bad-mouth emissions controls on cars, but to me it seemed like cars are getting more power (albeit smaller engines, but the horsepower to displacement ratio is bigger). From your answer, it would seem my confusion was not unfounded. I think electronic fuel-injection alone was a huge power-improver/energy-saver.

    Wow! Under-rating horsepower? Today, I think just the opposite is true (to some extent). Thanks again for the informative reply.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaPosts: 64,482
    About the only downside I can think of regarding computer-controlled cars today is that you can't fix them yourself anymore. Fortunately, usually you don't have to fix them, as they are amazingly reliable compared to older cars. Personally, I would rather accept an older's cars inefficiency for the privilege to repair it myself rather than give it to people who just mess it up anyway. Technologically, I'm at about 1990, I just can't handle fixing new cars, and by the time I get to learn all about the 99s, it'll be 2010. And you know, I think most repair shops are in the same boat I am, only they are maybe 3-4 years behind instead of my 10.
  • bobs5bobs5 Posts: 557
    I am technologically similar to you Mr Shiftright, but am in 1986 as this is the newest vehicle I have worked on.
    Having so much computer controlled stuff scares me.
    How do you know that the signals which the computer receives are correct?
    Like computers are: garbage in, garbage out.
    How many sensors do new vehicles have?
    The computer is good to find a totally bad sensor but I doubt that they can detect when a sensor starts to get flaky. ie:temperature or even moisture related problems.
    How can a person check sensors manually?
    Had a 1983 Ford LTD station wagon and you could not even check the timing with a timing light.
    Still miss my old 1963 Ford Falcon, even with the old ignition system, condenser,points,etc, it ran like a champ, never left me stranded. Can't say that about the newer vehicles I have had.
    Usually the tools required were a basic tool set and feeler gauges to tune up the old cars.
    Now the shops need extremely expensive and sophisticated computer analyzers just for a simple tune up.
    It annoys me when I read in the posts when a mechanic says "the computer says there is nothing wrong... sorry but I can't help you further".
    Seems they use the computer readout to support their "denial-fest", when actually there still is a problem.
    What ever happened to good old troubleshooting?
    I still prefer the old cars for relatively problem free performance and ease of working on.
    new cars seem overly computerized to me.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaPosts: 64,482
    To give you an idea...a modern car today has way more computing power than the 1969 Lunar Lander.

    I think you could still find an expert troubleshooter today, but he or she would be so smart they'd probably be doing something else for a living. Very few greasy geniuses left in America...we're in a clean-hands technological era.
  • This is one advantage to buying a pick-up truck (or fullsize SUV). Although they still have all that computer stuff, it still looks like a regular engine (Rear-wheel drive with V8 facing the right way and tons of room to work under the hood). I just added headers (the shorty, smog-legal variety) to my '98 GMC 5.7L and it was a breeze and I'm just a novice as mechanics go. I would not have even attempted that in a modern CAR.

    I agree about the greasy geniuses. Most of them are smart enough to have moved up to a position out of the garage. Can't say I blame them. I love working on my vehicles, but I'd hate working on Joe Public's car. I have a feeling that's how most mechanics feel.

  • rea98drea98d Posts: 982
    78 Merc with a 400 CID engine, factory rated at a whopping 163 horses! I'm eventually going to have to rebuild that engine as it is losing compression, power, and a quart of oil every 3,000 miles. Having it completely disassembled would be the best time to eliminate some of these smog controls and increase horsepower with some modern hardware. Adding fuel injection or throttle body injection sounds like a good idea, but will cost about 1200 bucks for even a simple system. I've also considered replacing that old mechanical distrubitor. What else could I add or eliminate on this engine to get more power while not creating any more pollutants than absolutely neccesary. (Shifty, I know it'll be cheaper to buy a new engine, but I'm just strange that way.)
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaPosts: 64,482
    I think you'll find that that engine has internal designs that will get in the way of horsepower. You'd certainly need to raise compression and rework the heads for better breathing, but you don't need fuel injection. The big dragsters don't use it (not allowed) and they do just fine with carburators. That old engine needs to breath in and breath out better.
  • stickguystickguy Posts: 40,834
    I always thought that in the good old days they rated HP in gross numbers, and switched at some point to net, which is why you can't compare the ratings (assuming no fibbing going on) of an old and new engine.

    Modern electronic controls more than make up for any losses related to smog controls these days, which primarily consists of a catalytic converter. Everything else mostly is designed to make the engine more efficient, which is a good thing.

    IMHO, one of the biggest differences is modern tires. Always wanted to see test results of a '60s Vette with the steamroller tires of a modern one vs. a '90s Vette wearing skinny little bias ply tires.

    2020 Acura RDX tech SH-AWD

  • rea98drea98d Posts: 982
    "Internal designs" Would we be talking about porting & polishing the heads, replacing intake & exhaust manifolds, or what? Just replace everything north of the engine block? 400 CID is a lot of engine to only get 160 HP. (Factory rating on the engine, beleive it or not!). I'll probably replace it at some point down the line, but for comparison, my T-Birds 4.6 liter engine has 119 fewer inches, but pull about 280 HP if memory serves.
  • rea98drea98d Posts: 982
    The T-Birds displacement in 280, the HP is around 205. (Still more than the Merc's bigger engine).
This discussion has been closed.